One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,8)(5,6)(9,10,14,18)(11,19,21,15)(12,16,13,17)(20,24,22,23)(25,26,31,36)(27,38,41,32)(28,42,45,33)(29,37,46,34)(30,35,40,48)(39,47,56,53)(43,49,55,51)(44,50,54,52)(9,11)(10,15)(12,20)(13,22)(14,21)(16,23)(17,24)(18,19)(25,27,31,41)(26,32,36,38)(28,43,45,55)(29,40,46,30)(33,49,42,51)(34,48,37,35)(39,54,56,44)(47,50,53,52)(2,6)(7,8)(9,12,14,13)(10,16,18,17)(11,20,21,22)(15,23,19,24)(25,28,29,44,31,45,46,54)(26,33,37,52,36,42,34,50)(27,39,30,43,41,56,40,55)(32,47,48,49,38,53,35,51)(1,3,5,4)(2,7,6,8)(9,12,14,13)(10,17,18,16)(11,20,21,22)(15,24,19,23)(25,29,31,46)(26,34,36,37)(27,40,41,30)(28,44,45,54)(32,48,38,35)(33,50,42,52)(39,55,56,43)(47,49,53,51)(1,4,5,3)(2,8,6,7)(9,13,14,12)(10,17,18,16)(11,20,21,22)(15,23,19,24)(25,30,46,27,31,40,29,41)(26,35,34,38,36,48,37,32)(28,43,54,39,45,55,44,56)(33,51,50,53,42,49,52,47)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.